FDA Panel Recommends Pfizer and Moderna Vaccines for Youngest Children

WASHINGTON – The only Americans still not eligible for coronavirus vaccines – babies, toddlers and preschoolers – appear on the verge of finally getting cleared to receive a Advisory Panel after the Food and Drug Administration voted unanimously on Wednesday to recommend Pfizer and Moderna vaccines. for the group.

The FDA appears poised to authorize Moderna’s vaccine for children younger than 6 and Pfizer’s for those younger than 5 as soon as Friday. States have already ordered millions of doses, and White House officials said shots could roll out as early as next week.

The committee’s 21-0 vote came after a daylong review of clinical trial data and the end of a process that involved months of false starts and dashed hopes for a vaccine to cover the youngest Americans. Except for roughly 20 million children under 5, everyone has had access to coronavirus shots for many months and is now eligible for booster shots.

The FDA and the Centers for Disease Control and Prevention jointly made a strong push for a positive recommendation, showcasing the committee with 230 pages of data that they said showed vaccines were safe and provoked a strong immune response in children. Regulators also emphasized that even though young children are generally at risk for serious illness from the virus, vaccinating groups will save lives.

“We have to be careful that we do not become numb to the number of pediatric deaths because of the overwhelming number of older deaths here,” Dr. Peter Marks, the FDA’s top vaccine regulator, said. “The intervention we’re talking about here is something that we have accepted in the past to prevent deaths from influenza,” he added.

Officials from the CDC said that more than half of young children hospitalized with Covid had no underlying medical conditions. During the winter in the Omicron wave, young children were hospitalized at a higher rate than children and adolescents, and their illness tended to be at least as severe. More than 200 children ages 6 months to 4 years old have died of Covid, according to death certificate data, one of the most conservative estimates.

The panel members, some of whom have treated hospitalized children for Covid and have comforted terrified parents, seem eager to act.

“There are so many parents who are absolutely desperate to get this vaccine,” said Dr. Jay Portnoy, a professor of pediatrics at the University of Missouri-Kansas City medical school. “I think we owe it to them to give them the choice.”

Dr. Arthur Reingold, an epidemiologist at the University of California, Berkeley, School of Public Health, said the nation already vaccinates children against diseases “where the risk of a child dying or being hospitalized was very close to zero.”

The CDC’s own panel of vaccine experts is set to take up the matter over two days this weekend. If that committee also gives a favorable recommendation, Dr. Rochelle P. Walensky, the agency’s director, would issue her decision, the final step in the process.

Neither vaccine has been tested against new sub-variants that are circulating in the United States. The clinical trials were largely conducted when the Omicron variant prevailed. Two subvariants, BA.4 and BA.5, could become dominant within a month.

The virus is evolving so fast that some panelists expressed fear that the clinical trial results on which their decisions were based were already outdated. “We’re really trying to predict the future,” Dr. Paul Offit, a vaccine specialist with the Children’s Hospital of Philadelphia and an FDA panelist, said in an interview. “This is a problem.”

But the panel’s biggest concern was whether Pfizer’s three-dose vaccine, which it developed with its German partner, BioNTech, was effective enough. Pfizer has reported that two doses of its vaccine were only about 28 percent effective in preventing symptomatic disease; Dr. Susan Wollersheim, an FDA reviewer, said the company’s data did not clearly show that the two doses drove down the incidence of Covid.

Pfizer argued that the three doses were 80 percent effective, but the finding was based on a subset of only 10 cases out of 1,678 trial participants. And Dr. Doran Fink, acting deputy director of the FDA’s office’s vaccines, cast doubt on the company’s estimates, describing it as “preliminary” and “imprecise.”

Still, he said the FDA was “very confident” from the immune response data that Pfizer’s vaccine, like Moderna’s, used to standardize emergency use authorization, which required benefits outweigh the risks. But some panel members were clearly worried that parents might be misled.

Dr. Amanda Cohn, a top CDC official and panelist, said she had “no idea” what the efficacy rate of the three doses of Pfizer would end up being, and that officials should not embrace the 80 percent estimate.

Jeannette Y. Lee, a biostatistician at the University of Arkansas for Medical Sciences, raised another concern: that some parents may skip the final dose for their children. “As we know, it’s a struggle to get people in for two,” she said.

Pfizer officials said the data showed the vaccine’s effectiveness built over time. “It’s not as if there’s no efficacy at all,” Dr. William C. Gruber, a senior vice president at Pfizer, said.

For some parents, the bar is low. Some more than 1,600 parents who responded to a New York Times query about life with an unvaccinated young child said they would accept any efficacy above zero to give their children some protection.

“To keep her safe from illness and potential death or lifelong hardship? Why is this a question? ” reply Cayla Miller, a mother in Swanville, Maine. “We’ve been waiting so long to protect our whole family. I’ve lost my job and my mind is trying to keep her safe. “

Scientists and federal officials are warning against directly comparing the Moderna and Pfizer vaccines. Not only did companies conduct their clinical trials at different times, with different populations, but the dosing and regimens differed.

Pfizer has proposed a three-dose regimen at one-third the strength of its adult dose, with the first two doses spaced three weeks and the third at least two months after the second. Moderna wants to offer two doses of vaccine, four weeks apart, at one-fourth the strength of its adult dose. Moderna’s adult dose is significantly higher than Pfizer’s.

Dr. Wollersheim’s FDA declined to answer when a panelist asked for a comparison of the vaccines’ effectiveness in young children. But as some parents may, some panelists try to do their own matchup.

Dr. Offit noted that Moderna’s efficacy data was slightly larger than Pfizer’s: about 51 percent effective in preventing symptomatic infections in children 6 months to 2 years old and 37 percent effective in children 2 through 5.

Even though protection against symptomatic infection was limited, he said, it was possible to predict that Moderna’s vaccine would ward off severe disease.

“I’m not so sure you can predict that with Pfizer’s vaccine,” he said. “I’m afraid they may have dosed under.”

Both vaccines provoke levels of neutralizing, or virus-blocking, antibodies among children comparable to those in young adults. Pfizer’s vaccine has been authorized for children 5 to 15 since last year, and regulators said it helped prevent hospitalization and deaths.

Still, both appear to be significantly less effective against symptomatic infections than adult vaccines when they were introduced 18 months ago. The FDA said that because Omicron proved far more adept at evading the vaccines’ defenses against infection than previous versions of the virus.

Given evidence of waning potency over time, the FD.A. He said that young children who get Pfizer and Moderna shots will need booster shots, just as older recipients have. That would mean Pfizer’s vaccine could wind up as four doses, while Moderna’s could have three.

Neither vaccine provokes serious safety concerns. The side effects of the vast majority were mild – irritability and crying, sleepiness, fatigue and loss of appetite. Recipients of Moderna’s vaccine appear more likely to experience fevers, but in line with those provoked by other pediatric vaccines, the FDA said.

Federal health officials said they expect many children to be vaccinated under 5 by pediatricians and primary care physicians, a contrast to older age groups. But the uptake is expected to be low; Children aged 5 to 11 became eligible to be vaccinated late last year, but only about 37 percent of them got at least one dose.

Doses are packaged by the hundred to reach smaller practices and rural locations. The Biden administration has also advertised a network of other locations that will work to reach families, including pharmacies and children’s hospitals, while groups such as the Association of Children’s Museums and the National Diaper Bank Network will help with education efforts.

One of the topics discussed in the FDA panel was how many parents’ children have already acquired some natural immunity. Federal health officials announced the committee this week suggesting that more than two-thirds of children aged 1 to 4 years old have already been infected with the virus.

A Moderna official told the committee that the company’s trial found that young children who had the virus and were vaccinated had greater levels of protection, a conclusion backed by outside research.

Dr. James EK Hildreth, a committee member and president of Meharry Medical College in Nashville, noted that many children were “infected and have done just fine.”

“But for those parents who choose to do so, especially for those parents with kids under conditions,” he added, “this is a choice they should have.”

Emily Erdos contributed reporting.

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